Characterization of $\mathrm{SiO_2}$ layers thermally grown on 4H-SiC using high energy photoelectron spectroscopy

Si 2p and C 1s core level spectra recorded at different electron emission angles from SiO2/SiC samples using a photon energy of 3.0 keV show two components. These are identified as originating from SiO2 and SiC for Si 2p while for C 1s they are identified to originate from graphite like carbon and SiC. The relative intensity of these components are extracted and compared to calculated intensity variations assuming different models for the elemental distribution in the surface region. For both samples investigated best agreement between experimental and calculated intensity variations with emission angle is obtained when assuming a graphite like layer on top of the oxide layer. Contribution from carbon at the SiC/SiO2 interface could not be identified